279 research outputs found

    G-quadruplex formation of FXYD1 pre-mRNA indicates the possiblity of regulating expression of its protein product

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    G-quadruplexes are higher-order nucleic acid structures formed of square-planar arrangements of four guanine bases held together by Hoogsteen-type hydrogen bonds. Stacks of guanine tetrads are stabilised by intercalating potassium ions. FXYD1 encodes for phospholemman, a regulatory subunit of the cardiac Na+/K+-ATPase. Computational sequence analysis of FXYD1 pre-mRNA predicted the formation of stable intramolecular G-quadruplexes in human and orthologue sequences. Multiple sequence alignment indicated that G-rich sequences are conserved in evolution suggesting a potential role of G-quadruplexes in FXYD1 gene expression. The existence of a non-functional alternative splicing product indicated that the G-quadruplex formation may control alternative splicing. Quadruplex formation of human and bovine oligonucleotides was confirmed in vitro by native polyacrylamide gel electrophoresis and intrinsic fluorescence emission spectroscopy. Taking together the evolutionary conservation of G-quadruplex forming sequences with the confirmation of G-quadruplex formation in vitro by two FXYD1 homologues the results point to a potential role of these structures in regulating the expression of FXYD1 and thus regulate indirectly the activity of the cardiac Na+/K+ -ATPase.Peer reviewe

    Cannabinoid signalling in TNF-alpha induced IL-8 release

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    Original article can be found at: http://www.sciencedirect.com/science/journal/00142999 Copyright Elsevier B.V. DOI : 10.1016/j.ejphar.2006.04.015Peer reviewe

    Inducible nitric oxide synthase mediates DNA double strand breaks in Human T-Cell Leukemia Virus Type 1-induced leukemia/lymphoma

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    BACKGROUND: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive and fatal malignancy of CD4(+) T-lymphocytes infected by the Human T-Cell Virus Type 1 (HTLV-1). The molecular mechanisms of transformation in ATLL have not been fully elucidated. However, genomic instability and cumulative DNA damage during the long period of latency is believed to be essential for HTLV-1 induced leukemogenesis. In addition, constitutive activation of the NF-κB pathway was found to be a critical determinant for transformation. Whether a connection exists between NF-κB activation and accumulation of DNA damage is not clear. We recently found that the HTLV-1 viral oncoprotein, Tax, the activator of the NF-κB pathway, induces DNA double strand breaks (DSBs). RESULTS: Here, we investigated whether any of the NF-κB target genes are critical in inducing DSBs. Of note, we found that inducible nitric oxide synthase (iNOS) that catalyzes the production of nitric oxide (NO) in macrophages, neutrophils and T-cells is over expressed in HTLV-1 infected and Tax-expressing cells. Interestingly, we show that in HTLV-1 infected cells, iNOS expression is Tax-dependent and specifically requires the activation of the classical NF-κB and JAK/STAT pathways. A dramatic reduction of DSBs was observed when NO production was inhibited, indicating that Tax induces DSBs through the activation of NO synthesis. CONCLUSIONS: Determination of the impact of NO on HTLV-1-induced leukemogenesis opens a new area for treatment or prevention of ATLL and perhaps other cancers in which NO is produced

    Impaired endogenous fibrinolysis at high shear using a point-of-care test in STEMI is associated with alterations in clot architecture

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    © The Author(s) 2019Impaired endogenous fibrinolysis is an adverse prognostic biomarker in acute coronary syndrome (ACS). Abnormally dense in vitro fibrin thrombi have been demonstrated in ACS patients and related to hypofibrinolysis using cumbersome, laboratory-based methods. We aimed to assess endogenous fibrinolysis using a point-of-care technique and relate this to clot architecture. From patients with ST-segment elevation myocardial infarction (STEMI), venous blood was drawn immediately on arrival to assess thrombotic status. Blood was assessed using the point-of-care Global Thrombosis Test which measures occlusive thrombus formation under high shear and subsequently endogenous fibrinolysis (lysis time, LT). Two samples per patient were run in parallel. In one channel, the measurement was allowed to proceed as normal. In the other, after occlusion, thrombus was extracted, washed, fixed in glutaraldehyde, dried, sputter-coated, and assessed using scanning electron microscope. Endogenous fibrinolysis was strongly associated fibrin fibre thickness (p = 0.0001). As LT increased (less efficient fibrinolysis), the fibrin network of the thrombus was significantly more compact and dense, with thinner fibrin fibres and smaller gaps. Fibrin fibre thickness correlated inversely with LT (r = - 0.89, p = 0.001). Adverse clot architecture in vitro is directly related to impaired endogenous fibrinolysis using a relatively new point-of-care technique in patients with STEMI. This may transform the relevance of fibrin clot architecture from an off-line laboratory association to being directly relevant to endogenous fibrinolysis at the patient bedside, which could be used as a near-patient test to guide prognosis and assess the effect of treatment.Peer reviewedFinal Published versio

    MicroRNAs in Cardiac Hypertrophy

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    Like other organs, the heart undergoes normal adaptive remodeling, such as cardiac hypertrophy, with age. This remodeling, however, is intensified under stress and pathological conditions. Cardiac remodeling could be beneficial for a short period of time, to maintain a normal cardiac output in times of need; however, chronic cardiac hypertrophy may lead to heart failure and death. MicroRNAs (miRNAs) are known to have a role in the regulation of cardiac hypertrophy. This paper reviews recent advances in the field of miRNAs and cardiac hypertrophy, highlighting the latest findings for targeted genes and involved signaling pathways. By targeting pro-hypertrophic genes and signaling pathways, some of these miRNAs alleviate cardiac hypertrophy, while others enhance it. Therefore, miRNAs represent very promising potential pharmacotherapeutic targets for the management and treatment of cardiac hypertrophy. - 2019 by the authors. Licensee MDPI, Basel, Switzerland

    Acute ST-segment elevation myocardial infarction in a young patient with essential thrombocythemia: a case with long-term follow-up report

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    Essential thrombocythemia (ET) is a neoplastic proliferation of mature myeloid cells - in particular, megakaryocytes - leading to persistently elevated platelet count. Usual clinical presentation is related to an increase in the risk of hemorrhage and/or thrombosis. Management of ET consists of antiplatelet therapies - mainly aspirin and cytoreductive therapies. Coronary involvement in patients with ET is rare. The optimal treatment strategies for ET patients presenting with acute myocardial infarction remains unclear. Acute interventions like intracoronary thrombolytic therapy, angioplasty, and coronary-artery bypass grafting have been reported in such patients. However, several questions remain unanswered about the acute and long-term management of these patients. Herein, we report the case of a 47-year-old female who presented with acute myocardial infarction as the first clinical sign of ET, and also present the long-term follow-up of this patient

    Jammer detection in M-QAM-OFDM by learning a dynamic Bayesian model for the cognitive radio

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    Communication and information field has witnessed recent developments in wireless technologies. Among such emerging technologies, the Internet of Things (IoT) is gaining a lot of popularity and attention in almost every field. IoT devices have to be equipped with cognitive capabilities to enhance spectrum utilization by sensing and learning the surrounding environment. IoT network is susceptible to the various jamming attacks which interrupt users communication. In this paper, two systems (Single and Bank-Parallel) have been proposed to implement a Dynamic Bayesian Network (DBN) Model to detect jammer in Orthogonal Frequency Division Multiplexing (OFDM) sub-carriers modulated with different M-QAM. The comparison of the two systems has been evaluated by simulation results after analyzing the effect of self-organizing map's (SOM) size on the performance of the proposed systems in relation to M-QAM modulation

    Neonatal Hypoglycemia in Diabetic Mothers: a Systematic Review

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    Hypoglycemia occurs in approximately 8-30% of neonates born to mothers with diabetes. The full extent of the individual and contextual risk factors of hypoglycemia remains unclear and no systematic review of the available studies exists to date. We identified published studies using PubMed and EBSCO host search engines. A modified STROBE statement was used to assess studies\u27 strengths, weaknesses, and generalizability. A total of 16 articles were eligible for full text review. The clinical risk factors in these studies were broadly classified into two: infant-related and mother-related risk factors. The identified infant-related risk factors were SGA, macrosomia, prematurity, lower cord blood glucose, ponderal index and male sex. On the other hand, mother-related risk factors includes maternal hyperglycemia, ethnic origin, diabetes diagnosed prior to 28 weeks of gestation, pre-pregnancy BMI of ≥ 25 kg/m², blood glucose, maternal diabetes type and maternal HbA1c. Irrespective of diabetes type, infants born to diabetic mothers appear to have a higher risk of developing hypoglycemia compare to those born to normal mothers. The overall evidence suggested that these studies mainly focus on the clinical characteristics of infants and mothers. Future research should focus on the identification of risk factors at the individual and contextual levels that can independently predict neonatal hypoglycemia. Appropriate emphasis should also be given to better define neonatal hypoglycemia

    Modulation of Macrophage Function by Lactobacillus-Conditioned Medium

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    open access articleProbiotics are used as microbial food supplements for health and well-being. They are thought to have immunomodulatory effects although their exact physiological mechanism of action is not clear. This study investigated the influence of probiotic Lactobacillus rhamnosus GG conditioned media (LGG-CM) on macrophage phagocytosis of non-pathogenic Escherichia coli HfrC. The gentamicin protection assay was used to study the bacterial killing phases of phagocytosis. Macrophages co-incubated with E. coli for an hour allowed them to ingest bacteria and then the rate of E. coli killing was monitored for up to 300 min to determine the killing or digestion of the bacteria by recovering them from the macrophage lysate. We found that the LGG-CM significantly increased the bacterial killing by approximately 6-fold when compared with that of controls. By contrast, this killing process was found to be associated with enhanced free radical production via the activation of NADPH oxidase, stimulated by the LGG conditioned medium. We also found that the conditioned medium had small effect on nitric oxide (NO) generation, albeit to a lesser extent. This work suggests that LGG-CM may play an important role in suppressing the total microbial load within the macrophages and hence, the extent to which pro-inflammatory molecules such as free radicals and NO are generated. The modulation of inflammation-promoting signals by LGG-CM may be beneficial as it modulates bacterial killing, and thereby prevents any collateral damage to host
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